Joined: Jan 30, 2011 Posts: 94 Location: Germany near Frankfurt/Main
Posted: Sat Dec 10, 2011 12:30 pm Post subject: Engine ID
The ID on the engine of my M38 is polished off.
But on the passenger side on the block are some numbers.
Is anybody there who can tell me, is this the ID of the engine?
Without the serial number on the flat above the water pump you will never be able to determine what model jeep it left Willys in.
The fact that is is one of the two casting numbers used on the M38 only qualifies it to fit in an M38. The very early versions of the 641087 casting with 4 freeze plugs, date clock and the oval serial pad on the top right side behind the oil filter would not have come in an M38. The numbers on the driver side will offer a clue as to date of manufacture but the block casting was used in several jeep models as well as the M38 simultaneously from Sept 1950 thru July 1952. So again without the serial number from the top of the block you can never ascertain what model it came in. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
Joined: May 10, 2010 Posts: 615 Location: North Yorkshire, UK
Posted: Sun Dec 11, 2011 9:39 am Post subject:
Quote:
The ID on the engine of my M38 is polished off.
It's possible the serial number might still be there. Try rubbing the serial number area with french chalk, and wiping it off with a dry cloth. Worth a try anyway. _________________ Owen
1951 US Air Force M38
1944 F-1 1/2-ton Airdrome Trailer
1940 C15 Chevrolet CMP 11-cab
1939 DKW KS200 Motorcycle
MVT # 19406
No, Vrod, No serial number means no way to tell which model it left Willys in. The basic block can have any accessories installed on it you want but since over 50 years have elapsed there's absolutely no other way to tell for sure except by the serial number. The bell housings will fit either block. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
There is no M38 block to bell housing special arrangement. The M38 engine bolted to the bell housing in 1950 the same way the CJ3A and CJ2A engine bolted to the bell housing. And the casting number on both was 641087.
The later (Dec51/MAR52) style rear block flange on the M38 641087 casting was exactly the same as the later (Dec51/MAR52) CJ3A 641087 casting.
The new block casting 804380 in 1952 was the same for both the M38 and the CJ3A.
As I have said there is only ONE way to determine without any doubt which model jeep a Willys engine casting came in> Yhe serial number
I can take any late CJ2A, CJ3A 641087 block casting and grind the pad above the water pump and duplicate the size, shape, depth and spacing of the MCXXXXX serial number and you cannot prove it is not an M38 block.
I think you are confusing the why and when and how of the 641087 block casting update in Dec/March 1952 from the four 3/8" rear flange bolts to the four 3/8" rear flange bolts plus 3 more per side 5/16" bolts. This was an across the Willys production line change that affected all models using that block at that time.
This 1950 thru Dec 51 641987 block was used in both the CJ3A and the M38 as well as other Willys products.
This Jan 1952 thru Jun 1952 641087 block was used in both CJ3A's and M38's and other Willys products.
This 804380 casting introduced in JUNE 1952 was used on both CJ3A and M38 and other Willys products. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
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